This invention relates to switch assembly structure for electrical machinery and more particularly to an improved switch assembly structure which can be utilized in a number of types of electrical machinery such as in conjunction with conventional centrifugal actuators for dynamoelectric machines.
As is disclosed and described in U.S. Pat. No. 4,034,173, issued to William D. Crow et al on July 5, 1977, a number of dynamoelectric machines, for example capacitor start and split phase induction motors, utilize a first winding combination for the "starting" condition of motor operation, and a second winding combination for the "run" condition of motor operation. These motors include a stator assembly and a rotor assembly, the rotor assembly including a shaft and the stator assembly including a plurality of windings. The selective energization of the windings is used to generate suitable forces for rotating the rotor assembly in both "start" and "run" conditions. As is known in the art, a centrifugal actuator mounted on the shaft is utilized to move a switch arm of a switch assembly mounted on a terminal board between a first position and a second position to ultimately cause selective electrical energization of the winding combinations.
As has been stated in the above-noted Pat. No. 4,034,173, some of the desirable features of switch assemblies utilized in such environments are that they be low in overall construction, assembly and maintenance cost, have contact pressure independent of switch arm position, provide for lost motion adjustment, permit ready internal motor mounting as an integral part of terminal board structure, be straightforward and simple in construction and maintenance, and, at the same time, eliminate or at least reduce false engagement of the various connections. The modified switch assembly structure of the present invention not only effectively incorporates most of these aforediscussed desired features, but, in addition, provides a switch assembly arrangement which ensures positive contact engagement for selected switch arm movement increments and yet, at the same time, substantially minimizes contact wear and breakage to reduce expensive construction, maintenance and replacement costs. In addition, the arrangement of the present invention ensures positive electrical contact engagement and continued maintenance of such positive electrical engagement notwithstanding often experienced impact and vibrations of machinery with which switch assembly arrangements are associated.
Various other features of the present invention will become obvious to one skilled in the art upon reading the disclosure set forth herein.